"I am but mad north-north-west: when the wind is southerly I know a hawk from a handsaw." --Hamlet, Act II, scene ii.

Thursday, 14 August 2008

Are the homeopaths getting there?

The new issue of Homeopathy (the in-house shitrag of the Faculty of Homeopathy) is out, which is always a joy. To my surprise, there's actually a paper in there that seems to be groping towards a vague sort of sense. The authors (Clare Relton and Alicia O' Cathain of the University of Sheffield, and Kate J. Thomas of the University of Leeds) seem to be on the cusp of imagining what homeopathy could actually be useful for. They don't say outright that the principles of homeopathy make no sense and that it doesn't work, but they do seem to be getting close to an idea of what might make homeopathy useful in the absence of specific effects from the wee sugar pills they give you. As we know, the evidence from the largest and best quality trials tells us that those pills don't do anything over and above the placebo effect. But what can we do with the placebo effect? In some ways, the paper is a missed opportunity, but there are at least signs of movement.

In the paper, the authors distinguish between several meanings of "homeopathy". Does it refer to the medicines? To consultations with a homeopath? To the principles of homeopathy? Or to the homeopathic therapeutic system as a whole? To be honest, I don't really care. But then the authors look at the definitions of 'efficacy' and 'effectiveness':

In clinical epidemiology ‘efficacy’ refers to ‘the extent to which a specific intervention, procedure, drug, regimen, or service produces a beneficial result under ideal conditions’. Evidence of efficacy is usually interpreted as requiring evidence from placebo-controlled randomised controlled trials (RCTs). Whereas ‘effectiveness’ is a ‘measure of the extent to which a specific intervention, procedure, drug, regimen or service, when deployed in the field in routine circumstances does what it is intended to do for a specific population’. Evidence of effectiveness requires pragmatic RCTs and well conducted observational studies of routine clinical practice.

The authors then argue that evidence of cost effectiveness, based on the clinical effectiveness of the intervention is required by NICE for interventions that are provided by the NHS, not evidence of efficacy. Then they go on to look at the evidence.

The authors divide the evidence into experimental evidence, by which they mean randomised, double-blind, placebo-controlled trials. This is where things go off the rails a bit. The authors suggest that looking at the 'active ingredient' of homeopathy as being the medicine given is far too reductionist; perhaps the active ingredient should be thought of as including "Six putative active ingredients... : patient's openness to the mind body connection, consultational empathy, in depth enquiry into bodily complaints, disclosure, the remedy matching process, homeopathic remedies". Not only that, but "Other authors have discussed the difficulties of separating out the effects of the homeopathic medicine from the consultation effects".

Now, this is interesting. It seems that what the authors are saying here is that much of the benefit that patients get from homeopathy is unrelated to the medicine they are given; it is related to the relationship between the homeopath and the patient, and to the consultation process. In medical science, there's a term for this: it's called the placebo effect. That's why you conduct placebo-controlled trials; because those effects exist, and you therefore need to separate them from the effect of the actual medicine that is given to the patients. That placebo-controlled trials are specifically designed to address this problem seems to have passed the authors by. Placebo-controlled trials of individualised homeopathy (i.e. the whole homeopathic package, including consulation) have been carried out, and show no better results than trials that did not include the consultation. But at least there is a recognition here that non-specific effects play a very large role in homeopathy.

The authors go on to look at what they call 'observational evidence', consisting of observational studies and case reports. The authors admit that this sort of evidence is "prone to many types of bias, it is regarded as weaker than experimental evidence, and is generally disregarded in systematic reviews of evidence". But they say "However, this type of evidence does acknowledge the homeopath i.e., focuses on treatment by a homeopath in contrast to the experimental evidence which focuses only on the homeopathic medicine".

This seems to be just the usual special pleading that 'my woo can't be tested by your cold-hearted science'. Then again, the authors do seem to be suggesting that the pills containing nothing are not as important as the context in which those pills are delivered. So where next? Unfortunately, the authors miss this opportunity by simply making some weak recommendations about terminology. But if the homeopathic community could admit that their drugs don't work, and sit down to figure out how they could strip out all the pseudo-science about energy medicine, water memory, quantum entanglement and so on, and how they could harness the power of the placebo effect, then what remained could conceivably be of some use.

Of course, that the homeopaths haven't managed to figure this out for themselves yet is a little surprising, given that this is what Ben Goldacre has been arguing for some time. It's also interesting to reproduce the last paragraph of the famous Shang et al. meta-analysis which was so damning of homeopathy:

"We emphasise that our study, and the trials we examined, exclusively addressed the narrow question of whether homoeopathic remedies have specific effects. Context effects can influence the effects of interventions, and the relationship between patient and carer might be an important pathway mediating such effects. Practitioners of homoeopathy can form powerful alliances with their patients, because patients and carers commonly share strong beliefs about the treatment’s effectiveness, and other cultural beliefs, which might be both empowering and restorative. For some people, therefore, homoeopathy could be another tool that complements conventional medicine, whereas others might see it as purposeful and antiscientific deception of patients, which has no place in modern health care. Clearly, rather than doing further placebo-controlled trials of homoeopathy, future research efforts should focus on the nature of context effects and on the place of homoeopathy in health-care systems."

Could the homeopathic and conventional medicine communities be moving towards common ground?

The homeopaths will never give up the magic in their little pills. It is interesting to note that Relton and Prof Thomas are on the 'scientific' committee of the Homeopathy 'Research' Institute. Their head Alex Tournier has not given himself a good reputation for canard-free interpretations of the evidence. And Lionel Milgrom is in the same group too. Milgrom might say the same thing as this paper but claim there are specific effects because of quantum do-da thingumy nano entanglements, or something.

Well, you're probably correct here. But it did strike me that what Relton et al. are saying seems remarkably similar to what Shang et al. said in 2005. As we know, Shang continues to be (wrongly) excoriated by the homeopathic community. Watch this space, I think...

I'm with Le Canard, at least as far as the lay homeopaths go. They simply cannot admit it is an elaborate placebo / stealth talking therapy, because then all their magic would be gone.

The medically-trained homeopaths over at the Faculty of Homeopathy are a different matter. Many (most?) of them clearly must understand that homeopathy is a placebo / ritual / crypto-psycho therapy. But again, they never admit this, at least not publically, and usually not until after they have retired (see Anthony Campbell). It is sometimes very hard, combing through Peter Fisher's utterances, to tell if he really, truly, believes that the homeopathic remedies do anything. If he does... well, I often think that the effort involved in the necessary Doublethink must make his head hurt.

Of course it matters enormously if homeopathy is 'merely a placebo'. Placebos do not treat illnesses, but alter peoples psychological reaction to that illness. There are limits and bounds to what is achievable with a placebo.

Homeopaths do not recognise this. They make unsubstantiated claims about efficacy for a wide range of illnesses when there is no evidence that these claims are true. That is why the homeopathic trade is systematically incompetent. This paper may be a baby step to correcting that.

But if it is acknowledged that homeopathy is a placebo we are into a new realm then where we have to grapple with the ethics of lying to patients. I, for one, do not want my GP lying to another patient about homeopathy because they think it will be good for them and then telling me they are being honest with me. Trust is rather blown out of the water.

Have to agree with the little black duck here. Is it really a good idea to be in a situation where we're giving out 'medicines' that we know don't work, and lying to patients about whether they work or not?

Personally, I find it difficult to see how the placebo effect could be useful, given these ethical issues. But it could be something worth talking about.

Of course, the other thing about homeopathy is all the pseudo-scientific notions that are associated with it. If you endorse homeopathy, you endorse the associated nonsense, and contribute to the corruption of public understanding of science and medicine.

And if it just a placebo maybe there are other better/cheaper placebos out there: cup of tea and a chat with a sympathetic frind or therapist; some physical exercise (if possible), etc.

Can lay-homeopaths justify the costs to their clients this way? What about the manufacturers - we know they may as well pump out a single type of sugar pill and pop them in bottles with the labels they want - but an explicitly post-pharmacological homeopathy wouldn't need anything but 'a single pill for all your ills'. A bit of a commercial honesty condundrum here I think!

Another reason why acknowledging the placebo effect is hard is that customers want to have a 'real treatment' for an exclusively physical condition. Not many want to be told that a psychological (or psychosocial) intervention might help them. That's interpreted as being told "it's all in your head".

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Welcome to Hawk/Handsaw...

This is the blog of Paul Wilson. You can find science- and pseudoscience-related things here, as well as occasional posts on my current research. There is also some stuff about what I do in my spare time (mostly cycling and complaining about politics).